STS-88 Day 3 Highlights

Endeavour's astronauts were awakened at 1:36 p.m. Central time today
to begin in earnest preparations for on-orbit assembly of the
International Space Station.

At about 3:50 p.m. Central time, Mission Specialist Nancy Currie
will power up the shuttle's 50-foot-long robotic arm and use it to
grapple the Unity connecting module, a procedure scheduled to begin at
4:06 p.m. Currie then will hoist the 12.8-ton Unity module out of
Endeavour's cargo bay and carefully place it in position perpendicular
to the shuttle. One of the mating adapters on Unity, called
pressurized mating adapter 1 (PMA-1), will be latched to Endeavour's
docking system using a mechanism identical to that used during
Shuttle/Mir dockings. Currie will maneuver Unity precisely to within a
few inches of the Shuttle's docking mechanism and then put the
mechanical arm into a "limp" mode. Commander Bob Cabana will then fire
Endeavour's thrusters to force the mechanisms together.

Preparations for tomorrow's capture of Zarya will continue as the
crew equalizes the air pressure between Endeavour and Unity's mating
adapter. The astronauts then will enter the adapter to install caps on
air vents between PMA-1 and Unity, and then readjust the Shuttle and
mating adapter's air pressure to about 10.2 pounds per square
inch. This equalization of air pressure between Unity's mating adapter
and Endeavour's cabin is done to provide better structural performance
of the docking mechanism during the capture and attachment of Zarya.

The crew also will perform a check of connections with the docking
mechanism located on the other end of Unity, called PMA-2, that will
attach to Zarya. For the check, the docking ring on that adapter will
be extended and retracted using controls located on the aft flight
deck of Endeavour. Unity and its two mating adapters will form a
complex 15 feet wide and about 36 feet long - taller than a 3-story
building - towering above Endeavour's payload bay.

This evening, astronautsJerry Ross and Jim Newman will check out
the various tools they will use during the three scheduled spacewalks
to be conducted later in the flight, and begin an early set-up of the
Shuttle airlock in preparation for that first spacewalk on
Monday. Later, Commander Bob Cabana and Newman will check equipment
needed for tomorrow's rendezvous with Zarya, including laptop computer
displays and a hand-held laser ranging device. Checks also will be
performed of the Orbiter Space Vision System, an alignment aid for
operations with the Shuttle's mechanical arm that will be used during
the capture and attachment of Zarya.

Newman and Russian cosmonaut Sergei Krikalev also will take time to
take part in an on-line interview by the New York Times at 11:01
p.m. Central time. Endeavour is trailing Zarya by about 7,600 statute
miles, narrowing the distance to the Russian-built module by almost
500 statute miles with each orbit. Endeavour is orbiting the Earth
every 90 minutes at an altitude of 202 statute miles. An engine firing
will be performed late today to raise the Shuttle's orbit and adjust
the rate at which Endeavour is closing in on Zarya, which is currently
in an orbit of about 240 statute miles. All of Endeavour's systems are
in excellent condition.

Astronaut Nancy Currie gently mated the 12.8-ton Unity connecting
module to Endeavour's docking system late Saturday afternoon,
successfully completing the first task in assembling the new
International Space Station.

The new connecting node, to which the Russian-built Zarya control
module will be mated later today, towered almost three stories over
Endeavour's cargo bay, awaiting the arrival of the Zarya, which was
launched from Kazakstan on Nov. 20 on a Russian Proton rocket.

After Unity was attached to the docking mechanism, the vestibule
running between Unity's PMA-2 and the Orbiter Docking System was
pressurized and the hatch was opened. Cabana and Jerry Ross entered
the new module's adapter for the first time and placed caps over vent
valves in preparation for the crew's entrance into Unity later this
week.

The astronauts also extended and retracted the docking ring on
PMA-1, to which the Zarya module will be mated after it is grappled by
Currie around 5:46 p.m. Central time this afternoon.

The grapple of Zarya will follow a carefully choreographed
rendezvous by Cabana and Pilot Rick Sturckow. Mission Specialists Jim
Newman and Sergei Krikalev will use a number of rendezvous tools and
hand-held lasers to provide range and closure rate information as
Endeavour narrows the gap between itself and the Zarya. The rendezvous
will begin about 12:30 p.m., with the final major maneuver planned for
about 3:14 p.m. This terminal initiation burn will place Endeavour on
a path to arrive about 500 feet below Zarya for the start of the final
phase of the rendezvous.

Working from the aft flight deck, Cabana will manually guide
Endeavour in a looping maneuver to a point 250 feet above Zarya, where
he will slowly close in on the 21-ton module for its grapple by
Currie. Zarya will be the heaviest object ever handled by the
shuttle's robot arm, exceeding the Compton Gamma Ray Observatory by
about 7,000 pounds.

Once Zarya is mated to Unity, the International Space Station
components will rise some 76 feet above Endeavour's bay and have a
combined weight of 35 tons. When it is fully assembled a few years
from now, the new station will span the length of a football field and
have a mass of more than a million pounds.

While Endeavour orbits the Earth at an altitude of about 241 by 134
statute miles, Zarya continues in orbit at an altitude of about 240
statute miles with all of its systems operating in excellent fashion.

Before the astronauts began an abbreviated 7-hour sleep period at
3:36 a.m. Central time, Cabana fired the shuttle's jets to keep a safe
distance from a spent Delta II rocket casing during the sleep
period. U.S. Space Command had alerted Mission Control that the
shuttle would be passing near the debris from a Nov. 6 launch of
communications satellites from Vandenberg Air Force Base, Calif., and
Flight Director John Shannon decided to have Cabana make the maneuver
to ensure the crew's sleep would not need to be interrupted.

When the crew awakens at 10:36 a.m. to begin preparations for their
rendezvous, Endeavour will be about 20 miles farther away from Zarya
than originally planned. However, the rendezvous burn schedule will
not be affected.